package com.firewolf.springboot;

import java.util.HashMap;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.bind.RelaxedDataBinder;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotationMetadata;

/**
 * 
 * 环境启动的时候，动态实例化出所有的数据源;
 * 
 * @author
 * 
 * @version v.0.1
 * 
 */

public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware {
	// 如配置文件中未指定数据源类型，使用该默认值
	private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource";
	private ConversionService conversionService = new DefaultConversionService();
	private PropertyValues dataSourcePropertyValues;
	// 默认数据源
	private DataSource defaultDataSource;
	private Map<String, DataSource> customDataSources = new HashMap<String, DataSource>();
	/**
	 * 
	 * 加载多数据源配置
	 * 
	 */
	@Override
	public void setEnvironment(Environment environment) {
		System.out.println("DynamicDataSourceRegister.setEnvironment()");
		initDefaultDataSource(environment);
		initCustomDataSources(environment);
	}
	/**
	 * 
	 * 加载主数据源配置.
	 * 
	 * @param env
	 * 
	 */
	private void initDefaultDataSource(Environment env) {
		// 读取主数据源
		RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, "spring.datasource.");
		Map<String, Object> dsMap = new HashMap<String, Object>();
		dsMap.put("type", propertyResolver.getProperty("type"));
		dsMap.put("driverClassName", propertyResolver.getProperty("driverClassName"));
		dsMap.put("url", propertyResolver.getProperty("url"));
		dsMap.put("username", propertyResolver.getProperty("username"));
		dsMap.put("password", propertyResolver.getProperty("password"));
		// 创建数据源;
		defaultDataSource = buildDataSource(dsMap);
		dataBinder(defaultDataSource, env);
	}

	/**
	 * 初始化更多数据源
	 * @create 2016年1月24日
	 */

	private void initCustomDataSources(Environment env) {
		// 读取配置文件获取更多数据源，也可以通过defaultDataSource读取数据库获取更多数据源
		RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, "custom.datasource.");
		String dsPrefixs = propertyResolver.getProperty("names");
		for (String dsPrefix : dsPrefixs.split(",")) {// 多个数据源
			Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix + ".");
			DataSource ds = buildDataSource(dsMap);
			customDataSources.put(dsPrefix, ds);
			dataBinder(ds, env);
		}
	}

	/**
	 * 
	 * 创建datasource.
	 * @param dsMap
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public DataSource buildDataSource(Map<String, Object> dsMap) {
		Object type = dsMap.get("type");
		if (type == null) {
			type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource
		}
		Class<? extends DataSource> dataSourceType;
		try {
			dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
			String driverClassName = dsMap.get("driverClassName").toString();
			String url = dsMap.get("url").toString();
			String username = dsMap.get("username").toString();
			String password = dsMap.get("password").toString();
			DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
					.username(username).password(password).type(dataSourceType);
			return factory.build();

		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 
	 * 为DataSource绑定更多数据
	 * @param dataSource
	 * @param env
	 * 
	 */

	private void dataBinder(DataSource dataSource, Environment env) {
		RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);
		dataBinder.setConversionService(conversionService);
		dataBinder.setIgnoreNestedProperties(false);// false
		dataBinder.setIgnoreInvalidFields(false);// false
		dataBinder.setIgnoreUnknownFields(true);// true
		if (dataSourcePropertyValues == null) {
			Map<String, Object> rpr = new RelaxedPropertyResolver(env, "spring.datasource").getSubProperties(".");
			Map<String, Object> values = new HashMap<>(rpr);
			// 排除已经设置的属性
			values.remove("type");
			values.remove("driverClassName");
			values.remove("url");
			values.remove("username");
			values.remove("password");
			dataSourcePropertyValues = new MutablePropertyValues(values);
		}

		dataBinder.bind(dataSourcePropertyValues);
	}

	@Override
	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
		System.out.println("DynamicDataSourceRegister.registerBeanDefinitions()");
		Map<Object, Object> targetDataSources = new HashMap<Object, Object>();
		// 将主数据源添加到更多数据源中
		targetDataSources.put("dataSource", defaultDataSource);
		DynamicDataSourceHolder.dataSourceIds.add("dataSource");
		// 添加更多数据源
		targetDataSources.putAll(customDataSources);
		for (String key : customDataSources.keySet()) {
			DynamicDataSourceHolder.dataSourceIds.add(key);
		}
		// 创建DynamicDataSource
		GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
		beanDefinition.setBeanClass(DynamicDataSource.class);
		beanDefinition.setSynthetic(true);
		MutablePropertyValues mpv = beanDefinition.getPropertyValues();
		// 添加属性：AbstractRoutingDataSource.defaultTargetDataSource
		mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
		mpv.addPropertyValue("targetDataSources", targetDataSources);
		registry.registerBeanDefinition("dataSource", beanDefinition);

	}

}